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Journal of Applied Microbiology Sep 2022To investigate the characteristics of two minority autochthonous LAB species, with particular regard to those properties that could be exploited in an improved cocoa...
AIMS
To investigate the characteristics of two minority autochthonous LAB species, with particular regard to those properties that could be exploited in an improved cocoa fermentation process from a quality and safety point of view.
METHODS AND RESULTS
Bacterial, yeast and mould strains characteristic of spontaneously fermented Dominican cocoa beans were isolated and identified by 16S or 26S rRNA gene sequencing. The potential of two autochthonous strains of LAB belonging to the species Lactiplantibacillus fabifermentans and Furfurilactibacillus rossiae were investigated. The two selected LAB strains were able to utilize glucose and fructose, produced mainly D-L lactic acid and had a good ability to resist to cocoa-related stress conditions such as low pH, high temperature and high osmotic pressure, as well as to grow in sterile cocoa pulp. The strains did not inhibit the growth of yeasts and acetic acid bacteria, that are essential to the cocoa fermentation process, and possessed a complex pool of peptidases especially active on hydrophobic amino acids. The strains also showed antifungal activity against mould species that can be found at the final stages of cocoa fermentation, as Aspergillus tamarii, A. nidulans, Lichtheimia ornata and Rhizomucor pusillus.
CONCLUSIONS
The tested strains are good candidates for the design of starter cultures for a controlled cocoa fermentation process.
SIGNIFICANCE AND IMPACT OF THE STUDY
This research showcases the potential of two alternative LAB species to the dominating Lactiplantibacillus plantarum and Limosilactibacillus fermentum as cocoa fermentation starters, with an interesting activity in improving the safety and quality of the process.
Topics: Bacteria; Cacao; Fermentation; Lactobacillus; Limosilactobacillus fermentum; Saccharomyces cerevisiae
PubMed: 35751485
DOI: 10.1111/jam.15687 -
Foods (Basel, Switzerland) Jan 2023In this study, the microbial diversity in Tibetan flavor was analyzed based on single molecule real-time sequencing (SMRT). The volatile flavor compounds in were...
In this study, the microbial diversity in Tibetan flavor was analyzed based on single molecule real-time sequencing (SMRT). The volatile flavor compounds in were detected using the headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). In addition, the correlation between various microbes and volatile flavor compounds was explored. Our studies indicated that the dominant bacterial genera in Tibetan flavor were , , , , , , , , and . The dominant fungal genera were , , and . 101 volatile compounds were detected in the samples, including alcohols, acids, esters, aldehydes, hydrocarbons, ketones, ethers, aromatics and pyrazines, and 10 key flavor compounds were identified using the relative odor activity value (ROAV). The results of our correlation analysis showed that was mainly associated with the synthesis of aldehydes such as trans-2-octenal, and was associated with the synthesis of most aldehydes. This paper has systematically investigated the physicochemical indices, microbial community structure and flavor compounds of Tibetan flavor , which is helpful in gaining a deeper understanding of the characteristics of Tibetan flavor .
PubMed: 36673416
DOI: 10.3390/foods12020324 -
IDCases 2020Mucormycosis is a rare fungal infection caused by Mucorales order fungi. The rhino-cerebral form of mucormycosis is most commonly seen in patients with diabetes...
Mucormycosis is a rare fungal infection caused by Mucorales order fungi. The rhino-cerebral form of mucormycosis is most commonly seen in patients with diabetes mellitus, whereas, pulmonary mucormycosis is a rare manifestation in patients with haematological malignancy and transplant recipients. We report a case of pulmonary mucormycosis presenting with a late acute onset diabetes on a patient immunosuppressed with a low dose of steroids. We aim to illustrate the need for a high clinical suspicion for the diagnosis of mucormycosis and to report the importance of early and aggressive inhiation of antifungal therapy.
PubMed: 33240790
DOI: 10.1016/j.idcr.2020.e00993 -
Indian Journal of Otolaryngology and... Jun 2023An invasive fungal infection caused by saprophytic and aerobic fungi Rhizopus, Rhizomucor, and Cunninghamella genera of the family Mucoraceae is known as Mucormycosis....
An invasive fungal infection caused by saprophytic and aerobic fungi Rhizopus, Rhizomucor, and Cunninghamella genera of the family Mucoraceae is known as Mucormycosis. Typically, Mucormycosis manifests in patients with conditions like uncontrolled diabetes, renal failure, patients receiving chemotherapy, long term steroid therapy or patients who are immunocompromised such as Acquired Immuno Deficiency Syndrome. The authors report a case of mixed opportunistic fungal infection of Mucormycosis and Aspergillosis following maxillofacial trauma that was treated by both medical and surgical line of management.
PubMed: 36777925
DOI: 10.1007/s12070-023-03492-z -
International Journal of Molecular... Jun 2022The behavior against temperature and thermal stability of enzymes is a topic of importance for industrial biocatalysis. This study focuses on the kinetics and...
The behavior against temperature and thermal stability of enzymes is a topic of importance for industrial biocatalysis. This study focuses on the kinetics and thermodynamics of the thermal inactivation of Lipase PS from and Palatase from . Thermal inactivation was investigated using eight inactivation models at a temperature range of 40-70 °C. Kinetic modeling showed that the first-order model and Weibull distribution were the best equations to describe the residual activity of Lipase PS and Palatase, respectively. The results obtained from the kinetic parameters, decimal reduction time (D and t), and temperature required (z and z') indicated a higher thermal stability of Lipase PS compared to Palatase. The activation energy values (Ea) also indicated that higher energy was required to denature bacterial (34.8 kJ mol) than fungal (23.3 kJ mol) lipase. The thermodynamic inactivation parameters, Gibbs free energy (ΔG), entropy (ΔS), and enthalpy (ΔH) were also determined. The results showed a ΔG for Palatase (86.0-92.1 kJ mol) lower than for Lipase PS (98.6-104.9 kJ mol), and a negative entropic and positive enthalpic contribution for both lipases. A comparative molecular dynamics simulation and structural analysis at 40 °C and 70 °C were also performed.
Topics: Burkholderia cepacia; Enzyme Stability; Kinetics; Lipase; Molecular Dynamics Simulation; Rhizomucor; Temperature; Thermodynamics
PubMed: 35743268
DOI: 10.3390/ijms23126828 -
Zhong Nan Da Xue Xue Bao. Yi Xue Ban =... Jul 2023Leukemia complicated with and coinfection is very rare, which is difficult to diagnose, and life-threatening. The clinical characteristics, diagnosis and treatment in... (Review)
Review
Leukemia complicated with and coinfection is very rare, which is difficult to diagnose, and life-threatening. The clinical characteristics, diagnosis and treatment in a child with acute myeloid leukemia (AML), who developed mucormycosis and aspergillus coinfection after chemotherapy, was reported. This case was a 12-year-old boy who presented with fever and cough during chemotherapy. and were detected in his blood, cerebrospinal fluid and alveolar lavage fluid by metagenomic next-generation sequencing (mNGS). Amphotericin B, posaconazole, and voriconazole were successively used for antifungal therapy. Skin debridement, bronchoalveolar lavage and local perfusion under bronchoscopy were performed. The infection of children was well controlled. The clinical manifestations of leukemia with mixed fungal infection are non-specific. The disease progresses rapidly and is prone to spread. Early diagnosis and treatment should be carried out. Combined antifungal therapy is recommended, and surgery is helpful to improve the patient's condition.
Topics: Male; Child; Humans; Mucormycosis; Coinfection; Antifungal Agents; Aspergillosis; Leukemia
PubMed: 37724414
DOI: 10.11817/j.issn.1672-7347.2023.230039 -
3 Biotech May 2023is a successful expression system that is frequently preferred in the secretion of proteins for both basic research and industrial purposes. In this study, recombinant...
is a successful expression system that is frequently preferred in the secretion of proteins for both basic research and industrial purposes. In this study, recombinant (RmASNase) L-asparaginase was produced in . The impact of gene copy number on increasing protein production was examined with six clones harboring various gene copy numbers (1-5 and 5 +). The results demonstrated that the clone with three copies of the expression cassette integrated had the highest production level. Also, biochemical characterization of the enzyme was performed. It was determined that the optimum pH and temperature values of the purified enzyme were pH 7.0 and 50 °C, respectively. Stability analyses of the enzyme showed that it maintains its activity of 80% in the pH range of 5-9 and 67% in the temperature range of 20-50 °C. Ca and Mn ions increased the enzyme activity to 121% and 138%, respectively. In future studies, it is also possible to improve the activity and stability values of the enzyme with advanced molecular techniques and to increase production efficiency by producing at fermenter scale and under optimum conditions.
PubMed: 37159589
DOI: 10.1007/s13205-023-03600-4 -
Mycologia 2019Corn bins in the midwestern United States can reach temperatures up to 52 C. High temperatures combined with sufficient moisture and humidity in bins provide the perfect...
Corn bins in the midwestern United States can reach temperatures up to 52 C. High temperatures combined with sufficient moisture and humidity in bins provide the perfect environment to promote the growth of thermophilic and thermotolerant fungi. In this article, we characterize for the first time thermophilic and thermotolerant fungi in corn grain bins using culture-based methods and pyrosequencing techniques. Corn samples were collected from local farms in western Illinois. Samples were plated and incubated at 50 C using a variety of approaches. Of several hundred kernels examined, more than 90% showed colonization. Species identified using culture methods included , and . Pyrosequencing was also performed directly on corn grain using fungal-specific primers to determine whether thermophilic fungi could be detected using this technique. Sequences were dominated by pathogenic fungi, and thermophiles were represented by less than 2% of the sequences despite being isolated from 90% of the grain samples using culturing techniques. The high abundance of previously undocumented viable fungi in corn could have negative implications for grain quality and pose a potential risk for workers and consumers of corn-derived products in the food industry. Members of the Sordariales were absent among thermophile isolates and were not represented in nuc rDNA internal transcribed spacer (ITS) sequences. This is in striking contrast with results obtained with other substrates such as litter, dung, and soils, where mesophilic and thermophilic members of the Sordariaceae and Chaetomiaceae are common. This absence appears to reflect an important difference between the ecology of Sordariales and other orders within the Ascomycota in terms of their ability to compete in microhabitats rich in sugars and living tissues.
Topics: Colony Count, Microbial; DNA, Ribosomal Spacer; Fungi; Hot Temperature; Illinois; Microbiological Techniques; Mycobiome; Phylogeny; Sequence Analysis, DNA; Whole Grains; Zea mays
PubMed: 31348716
DOI: 10.1080/00275514.2019.1631137 -
Frontiers in Nutrition 2022In this study, 18 standard amino acids were tested as a single nitrogen source on biomass, total lipid, total fatty acid (TFA) production, and yield of γ-linolenic acid...
In this study, 18 standard amino acids were tested as a single nitrogen source on biomass, total lipid, total fatty acid (TFA) production, and yield of γ-linolenic acid (GLA) in AUMC 11616.A and AUMC 6696.A isolated from unusual habitats. Grown for 4 days at 28°C, shaking at 150 rpm, the maximum fungal biomass for AUMC 6696.A was 14.6 ± 0.2 g/L with arginine and 13.68 ± 0.1 g/L with asparagine, when these amino acids were used as single nitrogen sources, while AUMC 11616.A maximum biomass was 10.73 ± 0.8 g/L with glycine and 9.44 ± 0.6 g/L with valine. These were significantly higher than the ammonium nitrate control ( < 0.05). The highest levels of TFA were achieved with glycine for AUMC 11616.A, 26.2 ± 0.8% w/w of cell dry weight, and glutamic acid for AUMC 6696.A, 23.1 ± 1.3%. The highest GLA yield was seen with proline for AUMC 11616.A, 13.4 ± 0.6% w/w of TFA, and tryptophan for AUMC 6696.A, 12.8 ± 0.3%, which were 38% and 25% higher than the ammonium tartrate control. The effects of environmental factors such as temperature, pH, fermentation time, and agitation speed on biomass, total lipids, TFA, and GLA concentration of the target strains have also been investigated. Our results demonstrated that nitrogen assimilation through amino acid metabolism, as well as the use of glucose as a carbon source and abiotic factors, are integral to increasing the oleaginicity of tested strains. Few studies have addressed the role of amino acids in fermentation media, and this study sheds light on and as promising candidates for the potential applications of amino acids as nitrogen sources in the production of lipids.
PubMed: 35592629
DOI: 10.3389/fnut.2022.876817 -
Molecules (Basel, Switzerland) Mar 2023Crude olive pomace oil (OPO) is a by-product of olive oil extraction. In this study, low-calorie structured triacylglycerols (TAGs) were produced by acidolysis of crude...
Crude olive pomace oil (OPO) is a by-product of olive oil extraction. In this study, low-calorie structured triacylglycerols (TAGs) were produced by acidolysis of crude OPO with medium-chain fatty acids (caprylic, C8:0; capric, C10:0) or interesterification with their ethyl ester forms (C8EE, C10EE). These new TAGs present long-chain fatty acids (L) at position -2 and medium-chain fatty acids (M) at positions -1,3 (MLM). Crude OPO exhibited a high acidity (12.05-28.75% free fatty acids), and high contents of chlorophylls and oxidation products. Reactions were carried out continuously in a packed-bed bioreactor for 70 h, using -1,3 regioselective commercial immobilized lipases ( lipase, Lipozyme TL IM; and lipase, Lipozyme RM IM), in solvent-free media at 40 °C. Lipozyme RM IM presented a higher affinity for C10:0 and C10EE. Lipozyme TL IM preferred C10:0 over C8:0 but C8EE over C10EE. Both biocatalysts showed a high activity and operational stability and were not affected by OPO acidity. The New TAG yields ranged 30-60 and the specific productivity ranged 0.96-1.87 g NewTAG/h.g biocatalyst. Lipozyme RM IM cost is more than seven-fold the Lipozyme TL IM cost. Therefore, using Lipozyme TL IM and crude acidic OPO in a continuous bioreactor will contribute to process sustainability for structured lipid production by lowering the cost of the biocatalyst and avoiding oil refining.
Topics: Olea; Plant Oils; Dietetics; Dietary Fats; Triglycerides; Fatty Acids; Olive Oil; Lipase; Esterification; Enzymes, Immobilized
PubMed: 36985609
DOI: 10.3390/molecules28062637